Titanium, copper, and aluminium are three metals extracted on a large scale using different metallurgical processes.
In the extraction of titanium from its main ore, rutile, several chemical reagents are used. Name the chemical element or compound that acts as: (i) The reagent (other than carbon) used to convert titanium(IV) oxide into titanium(IV) chloride. (ii) The reducing agent used to produce titanium metal from titanium(IV) chloride in the Kroll process.
The following chemical equations represent reactions occurring during the extraction of titanium and copper: A TiO2+2C+2Cl2→TiCl4+2CO\text{TiO}_2 + 2\text{C} + 2\text{Cl}_2 \rightarrow \text{TiCl}_4 + 2\text{CO}TiO2+2C+2Cl2→TiCl4+2CO B TiCl4+2Mg→Ti+2MgCl2\text{TiCl}_4 + 2\text{Mg} \rightarrow \text{Ti} + 2\text{MgCl}_2TiCl4+2Mg→Ti+2MgCl2 C FeO+SiO2→FeSiO3\text{FeO} + \text{SiO}_2 \rightarrow \text{FeSiO}_3FeO+SiO2→FeSiO3 D Cu2++Fe→Cu+Fe2+\text{Cu}^{2+} + \text{Fe} \rightarrow \text{Cu} + \text{Fe}^{2+}Cu2++Fe→Cu+Fe2+ E Cu2S+O2→2Cu+SO2\text{Cu}_2\text{S} + \text{O}_2 \rightarrow 2\text{Cu} + \text{SO}_2Cu2S+O2→2Cu+SO2
Choose from the letters A, B, C, D or E to answer the following. Each letter may be used once, more than once, or not at all. (i) A slag-forming reaction that removes iron(II) oxide impurities during copper smelting. (ii) A displacement reaction utilizing scrap iron to recover copper from aqueous solutions of low-grade ores. (iii) A highly exothermic reduction reaction that must be carried out under an inert argon atmosphere. (iv) A reaction that converts a metal oxide into a volatile liquid halide.
During copper extraction, slag collects as a waste layer. State the chemical name of the main compound present in this slag.
Aluminium is extracted from purified alumina (Al2O3\text{Al}_2\text{O}_3Al2O3) using electricity. (i) Why cannot carbon be used to reduce aluminium oxide to aluminium? (ii) Explain the purpose of adding cryolite to the aluminium oxide during electrolysis.
During the electrolytic extraction of aluminium, the carbon anodes must be replaced periodically. Explain why, writing a chemical equation to support your answer.
The overall extraction of aluminium by electrolysis is represented by:
2Al2O3→4Al+3O2 2\text{Al}_2\text{O}_3 \rightarrow 4\text{Al} + 3\text{O}_2 2Al2O3→4Al+3O2Write the two balanced ionic half-equations representing the reactions occurring at each electrode.
Half-equation 1 (at the cathode): Half-equation 2 (at the anode):
